It sounds wrong. E-cigarettes should be banned, says a long list of prestigious anti-tobacco groups including the American Cancer Society and the American Lung Association. But a federal court has stymied FDA efforts to keep them off the U.S. market.

Meanwhile, more and more Americans are buying e-cigarettes. And many of them say they've used the nicotine vaporizers to quit smoking real cigarettes, according to a new survey by Michael B. Siegel, MD, MPH, of Boston University School of Public Health.

"If you look at the evidence, these are a lot safer than regular cigarettes -- and they are effective for some people in helping them quit smoking cigarettes," Siegel tells WebMD.

Siegel and colleagues emailed surveys to 5,000 first-time buyers of Blu brand e-cigarettes. Replies came back from 222 of them (4.5%), of whom 216 said they were smokers.

Six months after their purchase, 31% of these smokers said they'd quit cigarettes and two-thirds of them said they'd cut back on the number of cigarettes they smoked. A third of those who'd quit smoking also quit using e-cigarettes.

Those are pretty impressive numbers, as only about 18% of smokers who quit actually do so for at least six months. But Siegel notes that a survey like this doesn't prove anything. All it can do is hint that maybe, just maybe, e-cigarettes can do some good.

Tobacco policy expert Michel Eriksen, ScD, director of the Georgia State University institute of public health, agrees with Siegel on this point. Eriksen, who was not involved in the Siegel study, is a former director of the CDC's Office on Smoking and Health.

It might have value. "The potential for electronic cigarettes in being helpful in smoking cessation is real but unestablished yet," Eriksen says.

What's needed is proof from rigorous studies, Siegel says. Proof that e-cigarettes really do help people quit smoking. And proof that e-cigarettes can safely be used as quit-smoking devices.

FDA Frustrated in Banning E-Cigarettes

E-cigarettes use a battery-driven heater to vaporize liquid nicotine and flavoring from a small cartridge. To make the vapor visible, the cartridges also dispense propylene glycol (PEG), commonly used for theatrical "smoke." Users puff or inhale the vapor from a mouthpiece.

To almost everybody, that sounds like a device for delivering nicotine. But because the nicotine is ultimately derived from tobacco plants, a federal court has ruled that e-cigarettes are -- legally speaking -- tobacco products and not nicotine-delivery devices.

Since they are tobacco products, the court ruled, the FDA lacks authority to regulate e-cigarettes as drugs or devices as long as they are marketed without claims of therapeutic effect.

This means that companies distributing e-cigarettes in the U.S. cannot sell their products as smoking-cessation devices, even though that is the only public health reason for their use.

"It is a bizarro world where the potential of e-cigarettes is not being realized for legal reasons," Eriksen says.

"This is a great public health opportunity," Siegel says. "You have companies willing to market the product as a smoking-cessation device. But they are wary of doing it because don't want to run afoul of the FDA."

Are E-Cigarettes Safe for Smoking Cessation?

Are e-cigarettes safe? The FDA thinks not, for several reasons:

E-cigarettes may get people, especially young people, addicted to nicotine, leading to cigarette use.

The cartridge may contain toxic ingredients. One FDA study did find a small amount of an antifreeze-like chemical in at least one cartridge, but Siegel points to 16 other studies that find no such contamination. "Based on identified chemicals and quantities, there is basically not anything of alarm," he says.

E-cigarettes have not been tested for efficacy and safety. Moreover, they are produced overseas with little oversight to ensure good manufacturing practices. "By being unregulated, there is no knowledge of the purity of what is being inhaled," Eriksen says. "It is a concern about the safety of this new behavior.

E-cigarette cartridges contain varying amounts of nicotine, so users don't know what dosage they are getting.

In a recent article, University of California, Riverside researchers Anna Trichounian and Prue Talbot, PhD, note additional safety concerns, such as leaky cartridges that get nicotine on users' fingers and confusing or absent instructions.

But what if e-cigarettes are used by people who want to quit or to cut back on real cigarettes? Just about the only thing on which all sides agree is that cigarettes are extremely dangerous -- not just because they deliver nicotine, but because they burn and deliver highly toxic combustion by-products.

"Everyone would agree that e-cigarettes are safer than traditional smoking," Eriksen says. "That does not mean they are safe. There may be other risks unknown at this point."

Siegel argues that if e-cigarettes are less harmful than real cigarettes, then people who smoke them instead of real cigarettes are reducing the harm they do to themselves. He points out that nicotine replacement patches and nicotine gum aren't totally safe, but that many people keep on using them even after they've stopped smoking cigarettes.

"If it's a choice between smoking and e-cigarettes, you are much better off with the e-cigs," Siegel says. "Even though this looks like smoking, it is a lot better than using regular cigarettes."

Can E-Cigarettes Help People Quit or Cut Back on Smoking?

Many e-cigarette users say the devices have helped them quit smoking, or at least cut back.

That's what scientists call "anecdotal evidence," i.e., not a proven fact. To remedy the gap in scientific evidence, Siegel is currently studying a group of e-cigarette users to see whether they're quitting or cutting back on real cigarettes.

However, only an expensive clinical trial could really determine how safe and effective e-cigarettes are for smokers who want to quit. U.S. e-cigarette distributors may be making money, but not that kind of money. Perhaps uniquely for this kind of product, they are not linked to tobacco or pharmaceutical companies. If there's going to be a clinical trial, there are no deep pockets to pay for it.

And why e-cigarettes? Why not nicotine gum, nicotine patches, or nicotine inhalers -- all of which have won FDA approval?

"The reason they seem to be so effective is because they simulate the physical act of smoking," Siegel says. "Smoking is a lot more than pharmacologic addition. If you talk to smokers, they will tell you there is more to it. The act of smoking, holding onto it, going through the motions, doing the inhaling -- even the social aspects of it, are all preserved with e-cigarettes."

"The e-cigarette has benefit of offering smoking behavior as well as nicotine delivery," Eriksen agrees.

And here's a compelling hint from Siegel's study. Among smokers who puffed e-cigarettes more than 20 times a day for six months, 70% said they'd quit smoking cigarettes.

"The promise e-cigarettes have needs to be explored objectively, and rational policies need to be developed," Eriksen says. "If they turn out to be helpful in getting people to quit smoking they should be made available for that purpose."

The Siegel article was published Feb. 8 online ahead of print by the American Journal of Preventive Medicine.